In metal forming equipment where workpieces move from a storage location to a workstation, aligning the workpieces to the forming device at the workstation can present problems.
Integrated into the tooling, inductive sensors with electrical connectors have been used for affecting workpiece/tooling alignment. A plug of the sensor must connect in a mating receptacle at the workstation.
Problems exist with automatic tooling changes since the input plug of the sensor, which normally mounts in a section of the tooling, must connect and complete a circuit within a receptacle mounted in a machine table of the workstation. When the tooling and the workpiece move on the machine table from a storage location to the workstation, and then to an output station, often after a period of time, wear and tear occur at the electrical connections. Hence, frequent line stoppage occurs when incomplete electrical connections exist.
Realizing the various problems associated with plug/receptacle wear and tear during automatic tooling changes, a search for various other means to achieve continuous and absolute electrical connections between the sensor plug in the tooling and the receptacle in the machine table was initiated. This search resulted in the improved contactless proximity switch arrangement of the present invention.